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 <20240522110909.10060-13-victorshihgli@gmail.com> <42f2b1d4-e6c2-4860-956d-4f10c3b05529@intel.com>
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From: Victor Shih <victorshihgli@gmail.com>
Date: Fri, 31 May 2024 18:32:00 +0800
Message-ID: <CAK00qKBA81zx=QmU7m=pZXOzdY4syOht4p_-SU7fdw+-an0ciQ@mail.gmail.com>
Subject: Re: [PATCH V16 12/23] mmc: sdhci-uhs2: add reset function function
To: Adrian Hunter <adrian.hunter@intel.com>
Cc: linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, 
	benchuanggli@gmail.com, HL.Liu@genesyslogic.com.tw, 
	Greg.tu@genesyslogic.com.tw, takahiro.akashi@linaro.org, dlunev@chromium.org, 
	Ben Chuang <ben.chuang@genesyslogic.com.tw>, 
	Victor Shih <victor.shih@genesyslogic.com.tw>, ulf.hansson@linaro.org
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On Fri, May 24, 2024 at 3:23=E2=80=AFPM Adrian Hunter <adrian.hunter@intel.=
com> wrote:
>
> On 22/05/24 14:08, Victor Shih wrote:
> > From: Victor Shih <victor.shih@genesyslogic.com.tw>
> >
> > Sdhci_uhs2_reset() does a UHS-II specific reset operation.
> >
> > Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
> > Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> > Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw>
> > ---
> >
> > Updates in V15:
> >  - Refer the SD Host Controller Standard Specification Section 3.10
> >    to add reset command data mechanism.
> >
> > Updates in V14:
> >  - Since mmc_card_uhs2() is the same as sdhci_uhs2_mode(), so drop
> >    sdhci_uhs2_mode() and use mmc_card_uhs2() instead of sdhci_uhs2_mode=
().
> >
> > Updates in V13:
> >  - Use ios timing to stead MMC_UHS2_SUPPORT for indicate the UHS2 mode.
> >
> > Updates in V8:
> >  - Adjust the position of matching brackets.
> >
> > Updates in V6:
> >  - Remove unnecessary functions and simplify code.
> >
> > ---
> >
> >  drivers/mmc/host/sdhci-uhs2.c | 57 +++++++++++++++++++++++++++++++++++
> >  drivers/mmc/host/sdhci-uhs2.h |  1 +
> >  drivers/mmc/host/sdhci.c      |  3 +-
> >  drivers/mmc/host/sdhci.h      |  1 +
> >  4 files changed, 61 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs=
2.c
> > index 9cb0f1b2a37d..7652158ea151 100644
> > --- a/drivers/mmc/host/sdhci-uhs2.c
> > +++ b/drivers/mmc/host/sdhci-uhs2.c
> > @@ -10,7 +10,9 @@
> >   *  Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
> >   */
> >
> > +#include <linux/delay.h>
> >  #include <linux/module.h>
> > +#include <linux/iopoll.h>
> >
> >  #include "sdhci.h"
> >  #include "sdhci-uhs2.h"
> > @@ -21,6 +23,8 @@
> >  #define SDHCI_UHS2_DUMP(f, x...) \
> >       pr_err("%s: " DRIVER_NAME ": " f, mmc_hostname(host->mmc), ## x)
> >
> > +#define UHS2_RESET_TIMEOUT_100MS             100000
> > +
> >  void sdhci_uhs2_dump_regs(struct sdhci_host *host)
> >  {
> >       if (!(mmc_card_uhs2(host->mmc)))
> > @@ -49,6 +53,57 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
> >  }
> >  EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
> >
> > +/*********************************************************************=
********\
> > + *                                                                    =
       *
> > + * Low level functions                                                =
       *
> > + *                                                                    =
       *
> > +\*********************************************************************=
********/
> > +
> > +/**
> > + * sdhci_uhs2_reset - invoke SW reset
> > + * @host: SDHCI host
> > + * @mask: Control mask
> > + *
> > + * Invoke SW reset, depending on a bit in @mask and wait for completio=
n.
> > + */
> > +void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask)
> > +{
> > +     u32 val;
> > +
> > +     sdhci_writew(host, mask, SDHCI_UHS2_SW_RESET);
> > +
> > +     if (mask & SDHCI_UHS2_SW_RESET_FULL)
> > +             host->clock =3D 0;
> > +
> > +     /* hw clears the bit when it's done */
> > +     if (read_poll_timeout_atomic(sdhci_readw, val, !(val & mask), 10,
> > +                                  UHS2_RESET_TIMEOUT_100MS, true, host=
, SDHCI_UHS2_SW_RESET)) {
> > +             pr_warn("%s: %s: Reset 0x%x never completed. %s: clean re=
set bit.\n", __func__,
> > +                     mmc_hostname(host->mmc), (int)mask, mmc_hostname(=
host->mmc));
> > +             sdhci_writeb(host, 0, SDHCI_UHS2_SW_RESET);
> > +             return;
> > +     }
> > +}
> > +EXPORT_SYMBOL_GPL(sdhci_uhs2_reset);
> > +
> > +static void sdhci_uhs2_reset_cmd_data(struct mmc_host *mmc)
> > +{
> > +     struct sdhci_host *host =3D mmc_priv(mmc);
> > +
> > +     sdhci_do_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
> > +
> > +     if (host->mmc->ios.timing =3D=3D MMC_TIMING_UHS2_SPEED_A ||
> > +         host->mmc->ios.timing =3D=3D MMC_TIMING_UHS2_SPEED_A_HD ||
> > +         host->mmc->ios.timing =3D=3D MMC_TIMING_UHS2_SPEED_B ||
> > +         host->mmc->ios.timing =3D=3D MMC_TIMING_UHS2_SPEED_B_HD) {
>
> Please use mmc_card_uhs2()
>

Hi, Adrian

     I will update this in the v17 version.

Thanks, Victor Shih

> > +             sdhci_uhs2_reset(host, SDHCI_UHS2_SW_RESET_SD);
> > +
> > +             sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
> > +             sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
> > +             sdhci_uhs2_clear_set_irqs(host, SDHCI_INT_ALL_MASK, SDHCI=
_UHS2_INT_ERROR_MASK);
> > +     }
> > +}
> > +
> >  /*********************************************************************=
********\
> >   *                                                                    =
       *
> >   * Driver init/exit                                                   =
       *
> > @@ -57,6 +112,8 @@ EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
> >
> >  static int sdhci_uhs2_host_ops_init(struct sdhci_host *host)
> >  {
> > +     host->mmc_host_ops.uhs2_reset_cmd_data =3D sdhci_uhs2_reset_cmd_d=
ata;
>
> As noted for patch 8, any host controller resets needed
> should be done before completing the request, so a call
> back function should not be needed.
>

Hi, Adrian

     I want to confirm further, so can I call
sdhci_uhs2_reset_cmd_data() directly
     in the mmc_wait_for_req_done()?
     Am I understanding something wrong?

Thanks, Victor Shih

> > +
> >       return 0;
> >  }
> >
> > diff --git a/drivers/mmc/host/sdhci-uhs2.h b/drivers/mmc/host/sdhci-uhs=
2.h
> > index 2bfe18d29bca..caaf9fba4975 100644
> > --- a/drivers/mmc/host/sdhci-uhs2.h
> > +++ b/drivers/mmc/host/sdhci-uhs2.h
> > @@ -177,5 +177,6 @@
> >  struct sdhci_host;
> >
> >  void sdhci_uhs2_dump_regs(struct sdhci_host *host);
> > +void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask);
> >
> >  #endif /* __SDHCI_UHS2_H */
> > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> > index 8fc3e001db74..f212da6dc2aa 100644
> > --- a/drivers/mmc/host/sdhci.c
> > +++ b/drivers/mmc/host/sdhci.c
> > @@ -236,7 +236,7 @@ void sdhci_reset(struct sdhci_host *host, u8 mask)
> >  }
> >  EXPORT_SYMBOL_GPL(sdhci_reset);
> >
> > -static bool sdhci_do_reset(struct sdhci_host *host, u8 mask)
> > +bool sdhci_do_reset(struct sdhci_host *host, u8 mask)
> >  {
> >       if (host->quirks & SDHCI_QUIRK_NO_CARD_NO_RESET) {
> >               struct mmc_host *mmc =3D host->mmc;
> > @@ -249,6 +249,7 @@ static bool sdhci_do_reset(struct sdhci_host *host,=
 u8 mask)
> >
> >       return true;
> >  }
> > +EXPORT_SYMBOL_GPL(sdhci_do_reset);
> >
> >  static void sdhci_reset_for_all(struct sdhci_host *host)
> >  {
> > diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> > index 13703f1a3710..83d994c8d89e 100644
> > --- a/drivers/mmc/host/sdhci.h
> > +++ b/drivers/mmc/host/sdhci.h
> > @@ -845,6 +845,7 @@ void sdhci_request(struct mmc_host *mmc, struct mmc=
_request *mrq);
> >  int sdhci_request_atomic(struct mmc_host *mmc, struct mmc_request *mrq=
);
> >  void sdhci_set_bus_width(struct sdhci_host *host, int width);
> >  void sdhci_reset(struct sdhci_host *host, u8 mask);
> > +bool sdhci_do_reset(struct sdhci_host *host, u8 mask);
> >  void sdhci_set_uhs_signaling(struct sdhci_host *host, unsigned timing)=
;
> >  int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode);
> >  int __sdhci_execute_tuning(struct sdhci_host *host, u32 opcode);
>